A radio access network (RAN) configuration has been changed such that various types of small cells such as a pico cell, a femto cell, etc. interact with a macro cell. The RAN configuration refers to a heterogeneous cell configuration or a hierarchical cell configuration in which small cells for low power/near field communication coexist in addition to an existing macro cell-based homogeneous network. An object of a new radio access network configuration is to increase QoE (Quality of Experience) in a manner of providing a high data transfer rate to a final user.
In small cell enhancements for E-UTRA and E-UTRAN study item (SI) as one of 3rd generation partnership project (3GPP) standard scopes, research has been ongoing into enhancement of indoor/outdoor scenarios using low power nodes, and the scenarios is described in 3GPP TR 36.932. In small cell enhancements for E-UTRA and E-UTRAN SI, research has been conduced to draw advantages of concept of dual connectivity to small cell layers and a macro cell layer in which a user uses the same or different carriers.
When the aforementioned trend is considered, users are more physically close to a network according to deployment of various small cells. Hence, it is expected that future communication is going to be performed via a user-centered virtual zone instead of a legacy cell of a base station in an enhanced 5G wireless access network. Moreover, in order to enable the communication via the user-centered virtual zone to be performed, it is necessary to induce a service providing unit differentiated from a legacy cell-based service providing unit. In particular, it is necessary to induce and solve technical issues capable of implementing such a service providing unit as a user-centered zone and the service providing unit may lead to a huge change of a current wireless access network.